NURS 6521 Week 1 Discussion: Pharmacokinetics and Pharmacodynamics

NURS 6521 Week 1 Discussion: Pharmacokinetics and Pharmacodynamics

NURS 6521 Week 1 Discussion: Pharmacokinetics and Pharmacodynamics questions and answers

As an advanced practice nurse assisting physicians in the diagnosis and treatment of disorders, it is important to not only understand the impact of disorders on the body, but also the impact of drug treatments on the body. The relationships between drugs and the body can be described by pharmacokinetics and pharmacodynamics.

Pharmacokinetics describes what the body does to the drug through absorption, distribution, metabolism, and excretion, whereas pharmacodynamics describes what the drug does to the body.

When selecting drugs and determining dosages for patients, it is essential to consider individual patient factors that might impact the patient’s pharmacokinetic and pharmacodynamic processes. These patient factors include genetics, gender, ethnicity, age, behavior (i.e., diet, nutrition, smoking, alcohol, illicit drug abuse), and/or pathophysiological changes due to disease.

For this Discussion, you reflect on a case from your past clinical experiences and consider how a patient’s pharmacokinetic and pharmacodynamic processes may alter his or her response to a drug.

Order NURS 6521 Week 1 Discussion: Pharmacokinetics and Pharmacodynamics Essay

To Prepare

• Review the Resources for this module and consider the principles of pharmacokinetics and pharmacodynamics.
• Reflect on your experiences, observations, and/or clinical practices from the last 5 years and think about how pharmacokinetic and pharmacodynamic factors altered his or her anticipated response to a drug.
• Consider factors that might have influenced the patient’s pharmacokinetic and pharmacodynamic processes, such as genetics (including pharmacogenetics), gender, ethnicity, age, behavior, and/or possible pathophysiological changes due to disease.
• Think about a personalized plan of care based on these influencing factors and patient history in your case study.
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By Day 3 of Week 1

Post a description of the patient case from your experiences, observations, and/or clinical practice from the last 5 years. Then, describe factors that might have influenced pharmacokinetic and pharmacodynamic processes of the patient you identified. Finally, explain details of the personalized plan of care that you would develop based on influencing factors and patient history in your case. Be specific and provide examples.

NB: Intro and conclusion to be included

By Day 6 of Week 1

Read a selection of your colleagues’ responses and respond to at least two of your colleagues on two different days by suggesting additional patient factors that might have interfered with the pharmacokinetic and pharmacodynamic processes of the patients they described. In addition, suggest how the personalized plan of care might change if the age of the patient were different and/or if the patient had a comorbid condition, such as renal failure, heart failure, or liver failure.

Discussion Rubric

Sample Essay 1

Patient Description

Mr. CJ is a 70-year-old Africa American who presented with bilateral weakness of the lower extremities of sudden onset in the emergency department. MRI imaging test of the spin revealed that the patient had lumbar spinal stenosis. Mr. CJ was immediately hospitalized in the neuro section for comprehensive evaluation and management. Mr. CJ had a past medical history of hyperlipidemia, type 2 DM, a cerebrovascular accident (CVA), hypertension. Mr. CJ’s drug regimen comprises of omeprazole 20mg PO OD, Coumadin 5mgPO OD, Flomax 0.4mg PO OD, atorvastatin 40 mg PO OD  at bedtime, hydralazine 25 mg PO TID, Finasteride 5 mg PO OD, and Keppra 500 mg PO BD. Mr. CJ  was a chronic smoker(24+pack years), and also took 22 oz. of beer daily.

Factors That Influence Pharmacodynamics and Pharmacokinetics

Pharmacokinetics describes the distribution, absorption, metabolism, and excretion of drugs. Its most important concept is drug clearance which describes the excretion/elimination of drugs from the body. Patients with GERD such as Mr. CJ often experience the regurgitation of gastric contents where substances such as bile salts, acid, and pepsin flow back to the esophagus from the stomach causing edema, irritation, and inflammation of the inner lining of the esophagus. This often results in upper GI bleeding and GI lesions and impairs the absorption of drugs. This increases the likelihood of failure to achieve the desired therapeutic outcomes. Tobacco smoking also increases the risk of development and progression of GERD. Ness-Jensen & Lagergren (2017) explain that, the nicotine present in tobacco relaxes the lower esophageal sphincter and this promotes digestive juices and stomach acids in the stomach to back up into the esophagus. It is also worth noting that, tobacco and alcohol contain carcinogenic substances. They cause ulceration and dyspepsia which negatively interfere with the absorption of drugs. Most drugs are metabolized in the liver by the P450 enzyme. According to Teschke (2018), excess consumption of alcohol can also result in liver cirrhosis which interferes with the metabolism of drugs. Impaired metabolism can subsequently impair the elimination of drugs, impair therapeutic action, and inactivate prodrugs. Besides, a patient with impaired drug metabolism has limited treatment choices. Pharmacokinetics is also influenced by age such that it reduces with the normal process of aging.

Pharmacodynamics refers to the dose-response relationship of drugs on human beings. Since Mr. CJ is on Coumadin, an anticoagulant, and had a past medical history of AFib and a CVA, it is important to maintain the INR (International Normalized Ratio) of 2-3 to prevent similar occurrences (AFib and CVA) in the future (Seiffge et al., 2019).  In case the patient’s INR   exceeds or goes beyond the required range, it will be important to adjust the dose of Coumadin.  This implies that the clinician will regularly monitor Mr. CJ’s INR to safeguard his safety by preventing his risk of bleeding. 

Individualized Care Plan

• Order for the following diagnostic tests; renal function test, INR, lipid panel, and HbA1C, and a liver function test (LFT).
• Closely monitoring blood pressure and blood glucose.
• Cardiac monitoring
• Withhold the administration of Coumadin 72 hours before and after surgical decompression
• Initiating IV heparin and gradually  introduce Mr. CJ to  oral Coumadin  when the INR levels are appropriate
• Monitor drug-drug interactions(omeprazole and Coumadin) and withdraw omeprazole if it increases the INR levels
• Educate the patient about  dietary considerations to   reduce the  severity  and  frequency of GERD symptoms
• Educate and closely monitor Mr. CJ for the signs and symptoms of a recurrent CVA.
• Collaborate with physical and occupational therapists to initiate Mr. CJ into therapy post-recovery. 
• Educate Mr. CJ on the essence of medication adherence in attaining therapeutic goals.

References

Teschke, R. (2018). Alcoholic liver disease: alcohol metabolism, a cascade of molecular mechanisms, cellular targets, and clinical aspects. Biomedicines, 6(4), 106.

Ness-Jensen, E., & Lagergren, J. (2017). Tobacco smoking, alcohol consumption, and gastro-oesophageal reflux disease. Best Practice & Research Clinical Gastroenterology, 31(5), 501-508.

Seiffge, D. J., Werring, D. J., Paciaroni, M., Dawson, J., Warach, S., Milling, T. J., & Norrving, B. (2019). Timing of anticoagulation after recent ischaemic stroke in patients with atrial fibrillation. The Lancet Neurology, 18(1), 117-126.

Sample Essay 2

As an Intensive Care Unit (ICU) nurse of 10 years, I have taken care of a variety of different people with a broad spectrum of illnesses and problems. Pharmacokinetics, or how the body processes a drug, must be carefully considered for the best treatment options (Rosenthal & Burchum, 2018). A typical patient diagnosis that can be particularly difficult to manage medically is drug and alcohol abusers. Their drug tolerances and organ impairment related to damage from abuse can make it especially challenging to treat their conditions.

I vividly remember taking care of a patient in their early 30s who was admitted to the medical intensive care unit that I worked in for alcohol withdrawal. He had no past medical history except for alcohol and benzodiazepine abuse. He was found by a family member in alcohol withdrawal and was immediately brought to the hospital. The clinical institute withdrawal assessment for alcohol scale (CIWA), was used to determine the severity of withdrawal. This scale views different symptoms of withdrawal such as nausea/vomiting, tremors, sweats, anxiety, agitation, visual and auditory disturbances, headache, and orientation (MERCK Manual Professional Version, 2020). His CIWA score was extremely high, which showed severe withdrawal.

Typical treatment for alcohol withdrawal includes the administration of benzodiazepines in order to get through the detox process. This drug helps lessen the withdrawal symptoms. When giving this patient a standard dose of benzodiazepines such as Ativan or Valium, there was no decrease in clinical symptoms. This was because of his history of benzodiazepine abuse and increased tolerance. Increased drug administration and frequency were ordered until the patient’s withdrawal symptoms were under control. However, the patient also had liver damage from alcoholic cirrhosis. Benzodiazepines are drugs that are metabolized by the liver (Brett & Murnion, 2015).  Since the liver was not functioning correctly, the medications administered to control alcohol withdrawal were not processed appropriately by the liver, causing a buildup of the drugs (Louvet & Mathurin, 2015). The patient became unresponsive, and an advanced airway was placed for airway protection.

I feel that this patient’s care could have been handled differently. Due to this patient’s history, a different plan of treatment should have been initiated. I feel that by following the standard protocol for alcohol withdrawal treatment, the outcome of this patient getting intubated was inevitable. However, the patient will remain unresponsive until his body cleared all of the benzodiazepine drugs. This could be a lengthy process and delay his care further. I would have suggested intubation and mechanical ventilation from admission, and to use sedation safe for the liver. By doing this, the patient would be able to overcome his detox safely and have his breathing tube removed sooner. This would decrease any other risks associated with prolonged mechanical ventilation.

References

Brett, J., & Murnion, B. (2015, October). Management of benzodiazepine misuse and dependence. Australian Prescriber, 38(5), 152-155. http://dx.doi.org/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4657308/

Louvet, A., & Mathurin, P. (2015, March 15). Alcoholic liver disease: mechanisms of injury and targeted treatment. Nature Reviews Gastroenterology, 12, 231-242. Retrieved from https://www.nature.com/articles/nrgastro.2015.35

MERCK Manual Professional Version. (2020). CIWA. Retrieved February 27, 2020, from https://www.merckmanuals.com/professional/multimedia/clinical-calculator/CIWA%20Ar%20Clinical%20Institute%20Withdrawal%20Assessment%20for%20Alcohol%20Scale

Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier.

Pharmacokinetics refers to the processes that the body subjects a drug to once administered. These processes include absorption, distribution, metabolism, and excretion. Contrarily, pharmacodynamics describes the effects that a drug has on the body, such as changes in the physiological processes and the side effects. The two processes are affected by different patient characteristics, such as age and gender. I have worked with the pediatric patient population and observed the two concepts in these patients. Lu and Rosenbaum (2014) define the pediatric population as consisting of neonates, infants, developing children, and adolescents. Their age affects pharmacokinetics and pharmacodynamics in various ways.

I have learned a lot from my experience with pediatric patient populations. First, the effective administration of drugs is tremendously challenging. This is because the rapid developments taking place inside the body have profound effects on pharmacokinetics and pharmacodynamics. For example, the gastric PH of a pediatric patient changes rapidly from birth through to childhood, which affects the efficiency of orally administered drugs. In addition, their physical size and physiological factors such, as membrane permeability, vary as the individual matures. In one instance, medicine administered to two children with similar conditions, and with an age differential of two months, had different results due to fast growth rate.

Administering drugs to pediatric patient population requires careful consideration of their unique physical and physiological characteristics. For example, the difference in the physical size between neonates and infants require that they are given different dosage sizes. Growth occurs very fast when the child is young, and it is critical to have the exact age and weight to administer the correct dosage. Another essential factor to consider in administering drugs is the PH of the gut. At birth, for example, gastric PH is neutral. Administering drugs to neonates should then consider the chemical composition of drugs administered orally to ensure they are effective (van den Anker et al., 2018). Every child should be treated uniquely as the rate of growth, and bodily changes vary.

References

Lu, H., & Rosenbaum, S. (2014). Developmental pharmacokinetics in pediatric populations. The Journal of Pediatric Pharmacology and Therapeutics, 19(4), 262-276.

van den Anker, J., Reed, M. D., Allegaert, K., & Kearns, G. L. (2018). Developmental changes in pharmacokinetics and pharmacodynamics. The Journal of Clinical Pharmacology, 58(10), S10-S25.

Response

Great job on explaining how medication administration can be influenced on patient factors such that of a pediatric patient. I work on the opposite end of the spectrum-gerontology patients so reading your discussion post was interesting and educational. I did some additional research on how medication administration and prescribing is different upon the pediatric population.

In review of literature one potential restraint that providers have when it comes to the pediatric patients is considering the likelihood that oral medications may be rejected due to the taste and texture that they are available in. It is essential for providers to understand the developmental pathway that occurs in terms of pediatric patients. According to Eidelman & Abdel-Rahman (2016), “the capacity to discriminate sweet and umami is present in utero, followed by texture, temperature and piquancy at 1–2 years of age and finally bitter, salty and sour around the age of 2 years. Olfactory senses do not appear to fully mature until children are 5–7 years of age. Other adaptive behaviors, which typically manifest by 2–5 years of age, influence a child’s willingness to accept novel foods, and by extension, medicines” (Eidelman & Abdel-Rahman, 2016, p.70). It is essential that providers are aware of all of the available forms and flavors that medications come in to ensure that medication is not rejected by the pediatric patient to ensure that the medication is effective. I found this factor interesting as it is not something that I would have considered or thought to consider prior to reviewing the content that is covered in this week’s material.

Cultural differences that may exist between the prescribing provider and the patient and their families should also be taken into consideration when prescribing medications. Many different cultures will often use traditional and herbal medications in addition to mainstream medications so having a clear understanding of these cultural differences and being able to ask appropriate questions to identify other health practices is essential as traditional and herbal medications can influence the effectiveness and interactions between the two treatment options (World Health Organization, 2007, p.10).

Eidelman, C. &.-R. (2016). Pharmacokinetic considerations when prescribing in children. International Journal of Pharmacokinetics, 69-80.

Organization, W. H. (2007). Promoting Safety of Medicines for Children. Geneva: WHO Press.